When I turn the hot water on in my shower, the pipes start humming. A few weeks ago it was a low rumble but has since then become something that resembles a whistle. How do I remedy this?
Thank you.
Jozbe

Go around the house and Close and Open all angle stops, including valve(s) at the water heater and main valve outside your house. Also, turn pressure regulator 1/4" in OPEN direction. See if that helped. Back to you. Milo